WP_Terms_List_Table displays empty pages with large hierarchical taxonomy

[csixty4]

I have a hierarchical taxonomy with 1,222 terms (oy!). In the admin (wp-admin/edit-tags.php?taxonomy=business_areas), the first five pages of terms display correctly (at 20 terms per page). But the sixth page on just show an empty table -- no terms.

Commenting out these lines in class-wp-terms-list-table.php prevents the empty display, but breaks the hierarchy:

if ( $term->parent != $parent && empty( $_REQUEST['s'] ) ) {
	continue;
}

Then I get a list like:

Musical Instruments and Repairs
— Brass Instruments and Repairs
— Bricklaying Services

…which tells me the terms are getting sorted by name, irrespective of the hierarchy. That might ultimately be the source of the problem.

[csixty4]

Duplicate of #14485.

Worked around this by calling delete_option('business_areas_children') at the end of the import so the cache gets rebuilt correctly.